(1) Field of the Invention
The invention generally relates to a television transmission system with a transmitter station and one or more TV receivers. More particularly, the invention is usable within a community antenna television (CATV) system in which given TV programmes are transmitted at the transmitter end in different TV channels by the CATV license to the CATV subscribers. The invention may, however, also be used in a system in which TV signals are transmitted by a satellite, a video recorder, a video camera, etc.
(2) Description of the Prior Art
The stations transmitted in a CATV system include formed on the one hand by stations which are received via a community antenna and on the other hand by locally generated stations. Since the total channel presentation is determined by the CATV licensed, this presentation may differ from CATV system to CATV system. In addition the presentation may be extended, or the CATV license may find it necessary for organizational reasons to transmit stations in a different TV channel.
As is known, in Europe most modern TV receivers are programmable. This means that they are provided with a non-volatile tuning memory having a number of addressable memory locations each comprising tuning data with each tuning datum being characteristic of a given TV transmission frequency band. Each memory location can be addressed by the user by operating one or a combination of a plurality of keys which are present on a control panel. Furthermore the receiver has a programming mode and a tuning mode. If the receiver is brought to the tuning mode and whenever a memory location is addressed, the tuning datum present therein is applied to a tuning circuit of the receiver which is thus tuned to the TV channel indicated by the tuning datum. For programming the tuning memory the receiver is first brought to the programming mode. For each station to be received the user can now store the tuning datum characterizing the channel in which it is provided in a user-addressed memory location of the tuning memory. The user must, however, be informed about the channels via which stations are transmitted in the CATV system. To this end many CATV licenses nowadays transmit a local information station via an information channel. If the user knows the number of this information channel he can tune the receiver to this information channel and thus obtain the desired data.